Mailchimp Sync Plugin not working

First I have installed the Mailchimp sync plugin on
It does not show as an option in your dropdown here so I have selected WPMU DEV Dashboard. I had to select something to send this.
I set it up .
API passed
Added webhook and added URL in mailchimp
The sync does not work and gives message: You are not allowed to do this action
When I add the sidebar widget and try to subscribe the wheel just turns forever and will not subscribe me. I have removed it for now.
Please help as I have exhausted all options and cannot find help in the forums.